1. Field of the Invention
This invention relates to a device for indicating the instantaneous water level in a closed vessel which contains water and steam or other gases.
2. Description of the Prior Art
The nuclear energy generation industry employs pressurized water reactors and boiling water reactors. Pressurized water reactors are intended to be substantially filled at all times with pressurized water at elevated temperatures. In the event of leakage or other failures in the system, it is possible for the pressurized water reactor to develop a steam bubble or a bubble of steam and other gases in the top portion of the reactor vessel. At the present time the reactor vessels are not equipped with apparatus or devices to provide instantaneous information to the system operator to indicate that a bubble has developed or to follow the growth of the bubble downwardly. In the boiling water reactors, there is a steam bubble at the top of the vessel above ebullient pressurized water. It is desirable for the operator to know the location of the upper level of the pressurized water. The violent agitation of the pressurized water prevents any precise definition of a water level at any one instant. However knowledge of the range of the oscillating water level is of value to the system operator.
Various suggestions have been made for using pressure differential devices to provide indications of the instantaneous water level in these pressure vessels. At the present time, there are no known water level indicator devices in any of the nuclear reactor reactors. The proposed devices appear to have many shortcomings, not the least of which is their initial expense.
There is a serious need for a water level indicator in nuclear energy generator vessels. There is a particular need for a reliable device with fail-safe features. There is a need for a device which will not interfere with the nuclear energy generation functions.